One-piece plywood corner unit



I il Juny 27, 1943,

H. MCGOWAN 2,325,528

ONE-PIECE PLYWOOD CORNER UNIT Filed May 17, 1941 2 Sheets-Sheet l Patented July 27.1943

2,325,528 oNE-Pmos rLYwoon coRNER UNIT Harold McGowamCentrai Islip, N. Y., assigner of i one-half to Bert Raskin, Brightwaters, N. Y.

Application May 17.1941, Serial No'. 394,022

s claims. (ci. 2in-92) The present invention relates to improvements in building constructions and has reference more particularly to a one-piece angular corner unit formed from plywood material.

One of the important objects of the invention resides in the provision of a one-piece angular plywood corner unit, which, when applied to the Vstuddingv of buildings will render the corners .crackproof, and at the same time compensate for the stresses and strains of the movement of contraction and expansion as well asfsettlement to which the walls and corners may be subjected.

Another object of the present invention is to provide a plywood corner unit of integral con-1 structionwhich canbe produced very economically, yet is strong and durable.

Other objects and advantages will become apparent from the accompanying drawings and description.

In the drawings, forming a part of this specification and in which like references designate corresponding parts, throughout the several views:

Figure 1 is a perspective view of the apparatus employed for treating and bending a sheet of the pre-channeled plywood material from which the corner unit is to be formed.

Figure 2 is a fragmentary front elevation of l the table, showing the perforated .steam pipes in section.

Figure 3 is a vertical sectional view taken approximately on the line 3-3 of Figure 2.

Figure 4 isa fragmentary transverse section through the table, showing a sheet of pre-channeled plywood material clamped thereon and ready forthe steam treatment.

Figure 5 is a view similar to Figure 4 showing the plywood sheet after having beensubjected to the steam -treatment and the outwardly projecting portion of the plywood sheet being bent downwardly.

Figure 6 is a fragentary perspective view of the pre-,channeled plywood sheet from which the corner unit is to be formed.

Figure '7 is a top plan view of my improved one-piece inside corner unit, and

Figure 8 is a similar view of an outside corner -unit constructedl in accordance with the present invention.

In the drawings, the numeral I designates'the work bench or table over the front edge of which extends a metallic angular straight edge 2. V A vertically movable clamping jaw 3 is arranged above the forward edge portion ofthe table. l

Springs 4 normally hold the clamping jaw 3 55 j in a raised position. Suitable screw-threaded rods 5 are mounted at their lower ends in suitable brackets E secured at the respective ends of the table and these rods extend upwardly and freely through guides 1, carried by the respective ends of the jaw 3. Handled sleeves 8 are threaded on the upper ends of the screws 5 and coact with the guides rior-moving the jaw 3 downwardly into clamping engagement with the plywood sheet. The springs normally hold the clamping jaw raised sufficiently izo-permit thelplywood sheet to be readily and easily positioned on the table.

A transversely movable clamping bar 9 is ad justably mounted on the upper face of the table I and the manner in which this bar engages and clamps the inner edge of' the plywood sheet is clearly illustrated in Figures 4 and 5 of the drawings.

The teme is formed with suitable slots lo to accommodate the fastening elements II, whereby the clamping bar 9 may be moved vandsecurecl in any transversely adjusted position on the ta- 'vble I.

Upper and lower steam pipes I2 and I3 extend longitudinally across the front ofthe table. The opposed sides of these steam pipes are formed with steam outlet openings I4 throughout the length of the steam pipes. These steam pipes may be supported in any suitable manner.

A steam supply pipe I5 delivers live steam from a suitable steam boiler I6 to the inner ends of thesteam pipes I2 and I3 while the outer ends of the perforated steam pipes have drain pipes I1 associated therewith. Adjacent their connection with the steam supply pipe I5. the steam pipes I2 and I3 have swivel joints I2' and I3' associated therewith to permit either steam pipe to be swung outwardly and away from the table when bending the steam heated plywood sheet.

A control valve I8 is associated with the steam supply pipe I5, and similar valves I8 and 2B are yassociated with the perforated steam pipes I2 and I3, as clearly shown in Figure 1 of the drawings.

With reference now to Figure 6, there is shown 'a sheet of plywood material 2| from which the corner unit is to be formed. In the instant case, a saw cut is made in the longitudinal center of the plywood sheet and this saw cut 22 extends from the top face to the approximate center of 'the thickness of the plywood sheet.

According to thequality of the center ply, the depth of the saw cut is adjusted so that the fibres of the center ply will break, forming a bridging when the pre-channeled plywood sheet is steam treated and bent. This bridging will make a good bond with the glue and filler or ceuniform -width extending from the outer' face thereof to its approximate center, said chani plywood sheet of material having a channel of threaded sleeves lare then actuated to bring the jaw 3 downwardlyinto clamping engagement with the upper face of the plywood sheet as clearly shown in Figure 4.

The valves I 8, i9 and 20 are then opened and live steam obtained from the boiler i6 enters the steam pipes I2 and I3, 'I'he openings Il cause jets of live steam to impinge against the channeled portion of the plywood sheet 2l, thereby thoroughly saturating the channeled portion 'of the plywood sheet with steam, whereby the outwardly projecting portion of the plywood sheet maybe easily bent down against the vertical face of the angular' metal piece 2 to dispose the portions of the sheet on opposite sides of the channel 22 at approximately lright angles to each other, as shown in Figure 5, and this with very slight pressure. When the lower steam pipe i3 is swung outwardly away from the table, the eoitened plywood sheet may be bent down against the front face of the table.

By operating the valves le and 2t, iets of steam may be omitted from either or both of the steam pipes. e I prefer to use live steam, it is to be understood that the channeled plywood sheet may be heated and softened by any other desirable .m for facilitating easy bending of the sheet.

also, the plywood sheet may be bent to form a corner' unit of any desired angular shape and l do not wish to limit myself to the forming of aioebend y.

titer the sheetoi plywood material has been bent on the machine, it is removed from the table and placed in a jack (not shown) and the channel ls then nlled with a suitable filler suchv as a. mixture oi Weldboard glue or any other binding cement, and when this is dry, the corner unit is ready for installation.

In Figure 7, there is shown what I term as an inside corner unit A. The filler is designated at 2b and a strip of canvas dit is lsecuredover the exposed face of the filler and the adjacent faces ci the plywood corner unit.

ln Figure d, an outside corner unit B is shown, the niler in this instnce being designated by the reference character" 25. i

it plywood vcorner unit" constructed in the aforementioned oharacter will prevent the rorrnaticn of cracks at corners in building wall The nller replaces the wood removed in cutting the channel formed in the plywood sheet at the outset, thereby restoring the original strength to the bent sheet and further holding the plywood sheet permanently to the angular shape to which it is bent.

While lhave shown the preferred embodiment of my invention, it is to be understood that various changes in the size, shape and arrangement of parts may be resorted to without departing from the spirirof the invention and the scope of the appended claims;

Having thus described my invention, what 'li claim is:

1. A corner unit for buildings, comprising a plywood sheet of material having a channel of uniform width extending from the outer face thereof to its approximate center, said channeled portion being bent to form angularly disposed wall portions, and a binder iilling said channeL said binder having its outer exposed face forming a continuation of the outer face of the angular walls of the corner unit.

8. A corner unit for buildings, comprising a plywood sheet of material having a channel of uniform width extending from the outer face thereoffto its approximate center, said channeled portion being bent to form angularly disposed wall portions, a binder illing said channel, said ybinder having its outer exposed face forming a continuation of the outer face of the angular walls of the corner unit, and a covering of exible material secured over the outer face of the' binder and the adiacent'areas of the outer faces of the angular walls.

d. A corner unit 'for buildings, comprising a plywood sheet of material formed of three united superposed plies, each of which is of substantially the same thickness, said plywood sheet having a channel extending from the outer face of the outermost ply to the approximate center of the intermediate ply, said plywood sheet being bent at its channeled portion to form a pair of angularly disposed walls, with the channel exposed at the outer side of the corner, and a cementltious filler in the channel lling the entire area thereof, the outer iace of the iiller lying iushv nel extending from the outer face oi the outertor most ply to the approximate center of theiutermediate ply, the side walls of the channel being straight, said plywood sheet being bent along its channeled portion to form a pair of angularly disposed side walls. with the channel exposed yat the outer side of the corner, said angularly disposed walls being adapted for disposition against the respective side wall studdngs on opposite sides of a cornerpost and the channeled corner portion oi the comer unit being adapted for disposition against said corner post.

6. A corner unit for buildings comprising a plywood sheet of material formed of three united -superposed plies, each of which is oi substantially the saine thickness, saidplywood sheet having a relatively narrow channel extending from the outer face of the outermost ply to the approximate center oi the intermediate ply, the side 

